chapters 16-17

What type of bonding is responsible for maintaining the shape of the tRNA molecule shown in the figure?

hydrogen bonding between base pairs

Which of the following types of molecules help to hold the DNA strands apart while they are being replicated?

single-strand DNA binding proteins

The sequence of nucleotides below is present at a DNA location where the chain opens to form a replication fork:

3' C C T A G G C T G C A A T C C 5'

An RNA primer is formed starting at the underlined T (T) of the template. Which of the following represents the primer sequence?

5' A C G U U A G G 3'

Which of the following statements accurately describes differences between DNA replication in prokaryotes and DNA replication in eukaryotes?

Prokaryotic chromosomes have a single origin of replication, whereas eukaryotic chromosomes have many.

Accuracy in translation of mRNA into the primary structure of a polypeptide depends on specificity in the ________.

attachment of amino acids to tRNAs

D

Which of the following is a reason that a new DNA strand elongates only in the 5' to 3' direction during DNA replication?

Dehydration reactions require a free -OH group.

What is the role of DNA ligase in the elongation of the lagging strand during DNA replication?

It joins Okazaki fragments together.

A replication error results in a zygote that has inactive telomerase, which of the following characteristics would you expect to see in the organism that develops?

a reduction in chromosome length in gametes

Which answer correctly compares the primary transcript in a prokaryotic cell with the functional mRNA?

the primary transcript is the same size as the mRNA

An mRNA molecule with the sequence 5'-CCG-ACG-3'is being read by a ribosome. During translation which of the following tRNA anticodons will be the first to productively bind with this mRNA?

3'-GGC-5'

Which of the following combinations of base pairs will be found in a molecule of DNA?

A + C = G + T

Which of the following processes occurs in prokaryotes but not in

eukaryotes?

simultaneous transcription and translation of the same mRNA

Rosalind Franklin's X-ray crystallography data suggested DNA is double stranded and has a uniform diameter. These observations can be used to rule out base pairing between two of the same nucleotide because ________.

an A-A pair is wider than a C-C pair

A section of DNA has the base sequence shown in #1. A mutation in this DNA strand results in the base sequence shown in #2. What type of mutation does this change represent?

#1 5' - AGCGTTACCGT-3'

#2 5'-AGGCGTTACCGT-3'

frameshift mutation

A particular triplet of bases in the template strand of DNA is 5'-AAA-3'. The anticodon on the tRNA that binds the mRNA codon is ________.

3'-AAA-5'

The most commonly occurring mutation in people with cystic fibrosis is a deletion of a single codon. What is the result of this type of mutation?

a polypeptide missing an amino acid

Which of the following changes in an exon is most likely to result in a nonfunctional protein product?

a base-pair deletion

Which of the following molecules directly participates in the process of translation?

mRNA, tRNA, and rRNA

Which of the following statements describes the effect of a nonsense mutation on a gene?

It introduces a premature stop codon into the mRNA.

Which of the following structural characteristics is most critical for the association between histones and DNA?

Histones are positively charged.

Which of the following characteristics allowed Hershey and Chase to determine whether the genetic material was made of DNA or protein?

DNA contains phosphorus, whereas protein does not.

What are telomeres?

the ends of linear chromosomes

In eukaryotes which of the following is the first step in translation?

the small subunit of the ribosome recognizes and attaches near the 5' cap of mRNA

What is the function of the release factor during translation in eukaryotes?

It binds to the stop codon in the A site in place of a tRNA.

Which of the following is a reason that the low error rate of DNA replication is important to evolution?

Rare errors are the source of variation.

Frederick Griffith heat-killed a culture of pathogenic bacteria. He split the sample and injected half of it into mice. The mice lived. He then mixed the other half with a living, nonpathogenic bacteria strain and injected the mixture into mice. The mice died. These results best support which of the following conclusions.

a substance had been transferred from pathogenic to nonpathogenic bacteria

Which of the following investigators was (were) responsible for determining that DNA contains equal amounts of adenine and thymine, and equal amounts of guanine and cytosine?

Erwin Chargaff

Which of the following properties is associated with a protein that will be secreted from a eukaryotic cell?

Its signal sequence must target it to the ER.

Once researchers identified DNA as the molecule responsible for transmitting heritable traits, they asked how information was transferred from the DNA in the nucleus to the site of protein synthesis in the cytoplasm. Which of the following statements correctly describes the mechanism of information transfer that accomplishes this task in eukaryotes?

Messenger RNA is transcribed from a single gene and transfers information to the cytoplasm, where protein synthesis takes place.

What amino acid sequence will be generated based on the following mRNA codon sequence?

5'-AUG-UCU-UCG-UUA-UCC-UUG-3'

Met-Ser-Ser-Leu-Ser-Leu

In E. coli, a mutation in a gene called dnaB prevents the helicase from binding at the origin of replication. Which of the following events would you expect to occur as a result of thismutation?

No replication fork will be formed.